Just one in 50 victims of America’s deadly drone strikes in Pakistan are terrorists – while the rest are innocent civilians, a new report claimed today.

The authoritative joint study, by Stanford and New York Universities, concludes that men, women and children are being terrorised by the operations ’24 hours-a-day’.

And the authors lay much of the blame on the use of the ‘double-tap’ strike where a drone fires one missile – and then a second as rescuers try to drag victims from the rubble. One aid agency said they had a six-hour delay before going to the scene.

The tactic has cast such a shadow of fear over strike zones that people often wait for hours before daring to visit the scene of an attack. Investigators also discovered that communities living in fear of the drones were suffering severe stress and related illnesses. Many parents had taken their children out of school because they were so afraid of a missile-strike.

Bombardment: More than 345 strikes have hit Pakistan’s tribal areas near the border with Afghanistan in the past eight years

Today campaigners savaged the use of drones, claiming that they were destroying a way of life.

Clive Stafford Smith, director of the charity Reprieve which helped interview people for the report, said: ‘This shows that drone strikes go much further than simply killing innocent civilians. An entire region is being terrorised by the constant threat of death from the skies.’

There have been at least 345 strikes in Pakistan’s tribal areas near the border with Afghanistan in the past eight years.

‘These strikes are becoming much more common,’ Mirza Shahzad Akbar, a Pakistani lawyer who represents victims of drone strikes, told The Independent.

‘In the past it used to be a one-off, every now and then. Now almost every other attack is a double tap. There is no justification for it.’

The study is the product of nine months’ research and more than 130 interviews, it is one of the most exhaustive attempts by academics to understand – and evaluate – Washington’s drone wars.

Tribesmen gather near a damaged car outside a house after a missile struck in Dandi Darpakheil village on the outskirts of Miranshah, the main town in the North Waziristan tribal region

Despite assurances the attacks are ‘surgical’, researchers found barely two per cent of their victims are known militants and that the idea that the strikes make the world a safer place for the U.S. is ‘ambiguous at best’.

Researchers added that traumatic effects of the strikes go far beyond fatalities, psychologically battering a population which lives under the daily threat of annihilation from the air, and ruining the local economy.

They conclude by calling on Washington completely to reassess its drone-strike programme or risk alienating the very people they hope to win over.

They also observe that the strikes set worrying precedents for extra-judicial killings at a time when many nations are building up their unmanned weapon arsenals.

The Obama administration is unlikely to heed their demands given the zeal with which America has expanded its drone programme over the past two years.

Washington says the drone program is vital to combating militants that threaten the U.S. and who use Pakistan’s tribal regions as a safe haven.

The number of attacks have fallen since a Nato strike in 2011 killed 24 Pakistani soldiers and strained U.S.-Pakistan relations.

Pakistan wants the drone strikes stopped – or it wants to control the drones directly – something the U.S. refuses.

Reapers and Predators are now active over the skies of Somalia and Yemen as well as Pakistan and – less covertly – Afghanistan.

But campaigners like Mr Akbar hope the Stanford/New York University research may start to make an impact on the American public.

‘It’s an important piece of work,’ he told The Independent. ‘No one in the U.S. wants to listen to a Pakistani lawyer saying these strikes are wrong. But they might listen to American academics.’

Today, Pakistani intelligence officials revealed a pair of missiles fired from an unmanned American spy aircraft slammed into a militant hideout in northwestern Pakistan last night.

The two officials said missiles from the drone aircraft hit the village of Dawar Musaki in the North Waziristan region, which borders Afghanistan to the west.

Some of the dead were believed to be foreign fighters but the officials did not know how many or where they were from.

The Monday strike was the second in three days. On Saturday a U.S. drone fired two missiles at a vehicle in northwest Pakistan, killing four suspected militants.

That attack took place in the village of Mohammed Khel, also in North Waziristan.

North Waziristan is the last tribal region in which the Pakistan military has not launched an operation against militants, although the U.S. has been continually pushing for such a move.

The Pakistanis contend that their military is already overstretched fighting operations in other areas but many in the U.S. believe they are reluctant to carry out an operation because of their longstanding ties to some of the militants operating there such as the Haqqani network.